Replacement for CL 7370053 which attempted to make fallthrough's
syntactically a part of switch statements. Because they may be
labeled, fixing that CL completely would require too much spec
surgery.

Fixes #4923.

R=r, iant, rsc, ken
CC=golang-dev
https://golang.org/cl/7416048

Also make the crossover point an architecture-dependent constant,
although it's the same everywhere for now.

BenchmarkAppendStr1Byte            416          145  -65.14%
BenchmarkAppendStr4Bytes           743          217  -70.79%
BenchmarkAppendStr8Bytes           421          270  -35.87%
BenchmarkAppendStr16Bytes          415          403   -2.89%
BenchmarkAppendStr32Bytes          415          391   -5.78%

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7459044

Update #3679.

BenchmarkAppend1Byte            484          199  -58.88%
BenchmarkAppend4Bytes           829          286  -65.50%
BenchmarkAppend8Bytes           484          365  -24.59%
BenchmarkAppend16Bytes          484          498   +2.89%
BenchmarkAppend32Bytes          486          484   -0.41%

R=iant, dave, rsc
CC=golang-dev
https://golang.org/cl/7443047

Fixes #4961.

R=golang-dev, r, minux.ma
CC=golang-dev
https://golang.org/cl/7443048

Fixes #4945.
Most examples in this issue now better, but #10 is incomplete and I'm not
certain how to reproduce it. It actually looks like a go/types problem, since
the type being reported is coming directly from that package.
Please reopen the issue if you disagree.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7448046

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7450049

Update #4961.

R=golang-dev
CC=golang-dev
https://golang.org/cl/7451044

R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/7429046

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7447044

R=gri, rsc
CC=golang-dev
https://golang.org/cl/7422051

Also: add support for pointer conversions, covered by one new test.

R=gri, bradfitz, dave
CC=golang-dev
https://golang.org/cl/7435047

Bridge methods for embedded interfaces were
passing the interface twice: once as receiver,
once as first param.
Covered by $GOROOT/test/ddd.go.

Also:
- invent names ("arg%d") for parameters if missing.
- refactoring: move common code for bridge methods into
  createParams and emitTailCall.

R=gri
CC=golang-dev
https://golang.org/cl/7437047

Update #4878.

R=golang-dev
CC=golang-dev
https://golang.org/cl/7450048

Update #4958.

R=golang-dev
CC=golang-dev
https://golang.org/cl/7434047

R=golang-dev
CC=golang-dev
https://golang.org/cl/7438052

Update #4955.

R=golang-dev
CC=golang-dev
https://golang.org/cl/7435049

Update #4956.

R=golang-dev
CC=golang-dev
https://golang.org/cl/7417048

Putting the M initialization in multiple places will not scale.
Various code assumes mstart is the start already. Make it so.

R=golang-dev, devon.odell
CC=golang-dev
https://golang.org/cl/7420048

Move the mstartfn into its own field.
Simpler, more likely to be correct.

R=golang-dev, devon.odell
CC=golang-dev
https://golang.org/cl/7414046

R=devon.odell
CC=golang-dev
https://golang.org/cl/7443046

Fixes #4948.

R=golang-dev, alex.brainman
CC=golang-dev
https://golang.org/cl/7445045

This time for sure.

R=golang-dev
CC=golang-dev
https://golang.org/cl/7449045

Distribute runnable queues, memory cache
and cache of dead G's per processor.
Faster non-blocking syscall enter/exit.
More conservative worker thread blocking/unblocking.

R=dave, bradfitz, remyoudompheng, rsc
CC=golang-dev
https://golang.org/cl/7314062

There is a #pragma dynexport crosscall2, to help SWIG,
and 6l cannot export the symbol if it doesn't get to see it.

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7448044

During my global search and replace I forgot to open *.S (capital).

R=golang-dev
TBR=golang-dev
CC=golang-dev
https://golang.org/cl/7415047

Switch to new pragma names, but leave old ones available for now.
Merge the three cgo-related sections in the .6 files into a single
cgo section.

R=golang-dev, iant, ality
CC=golang-dev
https://golang.org/cl/7424048

R=golang-dev, rsc
CC=golang-dev, minux.ma
https://golang.org/cl/7424047

Fixes #4950.

R=golang-dev, peter
CC=golang-dev
https://golang.org/cl/7415046

Fixes #4930.

R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/7424043

- implement windows pread;
- set correct Fhdr.type;
- add ImageBase to all pe "virtual" addresses;
- correct settext parameter order;
- use pclntab/epclntab to find line numbers.

Fixes #4841.
Fixes #4926.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7405050

R=golang-dev, dave
CC=golang-dev
https://golang.org/cl/7439048

Now that untyped expressions are done in two phases, the
identity of operand.expr is used as a map key; when reusing
operand values we now must be careful to update the
expr field.

R=gri
CC=golang-dev
https://golang.org/cl/7444049

Fixes #4767

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/7435046

R=golang-dev, nigeltao, adg
CC=golang-dev
https://golang.org/cl/7444048

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/7454044

R=r
CC=golang-dev
https://golang.org/cl/7442045

net/http/cookiejar.

This is a straight rename. There are no code changes.

Fixes #1960.

R=rsc, adg
CC=dr.volker.dobler, golang-dev
https://golang.org/cl/7436043

Fixes #4942.

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/7444047

Completely rethought shift expression type checking.
Instead of attempting to type-check them eagerly, now
delay the checking of untyped constant lhs in non-
constant shifts until the final expression type
becomes clear. Once it is clear, update the respective
expression tree with the final (not untyped) type and
check respective shift lhs' where necessary.

This also cleans up another conundrum: How to report
the type of untyped constants as it changes from
untyped to typed. Now, Context.Expr is only called
for an expresion x once x has received its final
(not untyped) type (for constant initializers, the
final type may still be untyped).

With this CL all remaining std lib packages that
did not typecheck due to shift errors pass now.

TODO: There's a lot of residual stuff that needs
to be cleaned up but with this CL all tests pass
now.

R=adonovan, axwalk
CC=golang-dev
https://golang.org/cl/7381052

And add a benchmark where #goroutines>GOMAXPROCS,
because it's the most interesting case.
Current results on darwin/amd64, Intel Core 2 Duo 2.13 GHz, 2 cores:
BenchmarkSyscall	100000000	        56.0 ns/op
BenchmarkSyscall-2	50000000	        57.2 ns/op
BenchmarkSyscallWork	10000000	       635 ns/op
BenchmarkSyscallWork-2	10000000	       315 ns/op
BenchmarkSyscallExcess	 1000000	      2698 ns/op
BenchmarkSyscallExcess-2	 5000000	      1192 ns/op
BenchmarkSyscallExcessWork	 1000000	      2832 ns/op
BenchmarkSyscallExcessWork-2	 2000000	      1966 ns/op

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/7415044